1. Field of the Invention
The present invention relates to control mechanisms for a group of generators which supply a motor vehicle electrical system.
2. Description of Related Art
Most of the known strategies for the symmetrical parallel operation of generators are based on a central control structure having a single regulating master generator or having a central controller and multiple slave generators, which are directly controlled by this central unit. In this case, the master generator or the central controller determines the required workload of the master generator according to a defined strategy and outputs a controlling signal to the slave generators. The slave generators thus receive a specification signal, according to which they are operated, without feedback to the master for the control being provided. The entire regulation intelligence is thus provided in a central unit (in the master generator). In the case of such a system architecture, the total system overview is provided in the master, which activates the slave generators accordingly. The activation strategy of the master is also provided within the master, the slave generators operating according to the specifications output by the master.
For example, published German patent application document DE 10 2007 037 355 A1 describes such a system architecture, in which a central control unit takes over all control tasks and monitoring tasks. The subordinate generators operate according to a benchmark which is output by the central control unit.
However, the disadvantage is inherently linked to the central architecture that all lower-order generators depend on the operation of the central controller or the master generator, so that in case of interference with the central transmission or interference with the central control unit for lack of activation, all lower-order generators also fail. Furthermore, in the case of a high number of lower-order generators, the processing of the particular transmitter signals by the central control unit is complex, so that particularly high requirements with respect to the computing output exist for the central controller. It is therefore an object of the present invention to provide an activation mechanism for a group of generators which does not have these disadvantages or in which the disadvantages are mitigated.